[NFC] Remove LinkAll*.h

These were added to prevent functions from being removed by WPO.

But that doesn't make sense, correct WPO will not remove functions we actually use.

I noticed these because compiling cc1_main.cpp was pulling in random LLVM pass headers.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D112971

Author: aeubanks

clang/tools/driver/cc1_main.cpp

@@ -27,7 +27,6 @@
 #include "clang/FrontendTool/Utils.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Config/llvm-config.h"
-#include "llvm/LinkAllPasses.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"

llvm/docs/WritingAnLLVMPass.rst

@@ -1308,11 +1308,6 @@ option.  Registering instruction schedulers is similar except use the
 ``RegisterScheduler::FunctionPassCtor`` is significantly different from
 ``RegisterRegAlloc::FunctionPassCtor``.
 
-To force the load/linking of your register allocator into the
-:program:`llc`/:program:`lli` tools, add your creator function's global
-declaration to ``Passes.h`` and add a "pseudo" call line to
-``llvm/Codegen/LinkAllCodegenComponents.h``.
-
 Creating new registries
 -----------------------